What are virtual functions in C++ inheritance?

What are virtual functions in C++ inheritance?

Virtual functions are member functions in a base class that you expect to override in derived classes. They enable polymorphism.

Can you give me an example of how to use virtual functions?

Sure! Here's a simple example:

class Base {
public:
    virtual void show() {
        cout << "Base class show function called.";
    }
};

class Derived : public Base {
public:
    void show() override {
        cout << "Derived class show function called.";
    }
};

int main() {
    Base* b;
    Derived d;
    b = &d;
    b->show(); // Calls Derived's show()
}

What happens if I don't use the virtual keyword?

If you don't use the virtual keyword, the base class's version of the function will be called, even if you have overridden it in the derived class.

Are there any performance implications of using virtual functions?

Yes, there can be a slight performance overhead due to dynamic dispatch, but it's often negligible compared to the benefits of polymorphism.